A snow plow and a winch are common vehicle accessories. Previously, a choice had to be made between which accessory was mounted for use on the vehicle. During the cold weather months, there is often a need for both a snow plow and winch to be mounted on the vehicle simultaneously. Problems arise when combining these two accessories on the front of a vehicle because they compete for space and in operation may interfere with each other. The winch is typically located on or near the vehicle frame which typically lies below the top of a snow plow mouldboard. To operate the winch when the snow plow is present, the winch cable must travel up and over the mouldboard. Previous devices employing pulleys and/or guides to accomplish this have proven unsatisfactory. Typically, these devices reduce the horizontal pulling force of the winch because the winch cable does not travel in a straight path between the winch drum and the object to which the cable is attached These devices may also cause increased wearing of the winch cable and any guides employed. Because these devices alter the travel path of the winch cable, they must be designed to withstand the very heavy loads that the winch cable is capable of transmitting.
Prior art devices in this area include the device shown and described in U.S. Pat. No. 4,215,496 which discloses a vehicle bumper permitting simultaneous mounting of a winch and a snow plow. That device threads the winch cable over a snatch block mounted on the plow lift arm to provide vertical clearance between the winch cable and the top of the snow plow. With this arrangement a large load on the cable will place a significant horizontal force on the plow bow member at a large height above the vehicle frame. The resulting stress or torque may, in time, cause the bow to fail. U.S. Pat. No. 2,803,071 discloses an adjustable, manually guidable snow plow. U.S. Pat. Nos. 3,587,751, 2,420,591, 2,166,424, and 1,776,788 disclose snow plows that are designed to allow the blade portion to travel over objects on the plowing surface avoiding damage to the snow plow. Cables are used in these devices to lift or guide the snow plow blade.
The present invention allows the winch to be operated without removing the snow plow. This device allows the winch cable to travel in a straight or very nearly straight path reducing the amount of lost horizontal pulling force in the winch cable. It also reduces the amount of wear on the winch cable and guides. Strength considerations for the portions of the device that allow the cable to travel over the mouldboard are reduced in the present invention because very few parts are subjected to heavy loads during the winching operation.
These and other advantages of the invention over the prior art will become more apparent after reading the description and claims which follow.